MIL-STD-1553B ("1553") defines an asynchronous serial, command/response digital data bus on which messages are time division multiplexed among users. The transmission medium is a twisted wire cable pair. 1553 specifies all of the electrical characteristics of the receivers, transmitters, and cable used to implement the bus, as well as the complete message transmission protocol. 1553 is designed for high integrity message exchanges between unattended equipment. The messages are highly repetitive, and their content and periodicity are all pre-planned.
The United States Department of Defense ("DoD") requires the use of 1553 as the standard for all inter and intra-subsystem communications on all military airplanes, helicopters, ships and land vehicles. Originally used only in mission avionics, 1553 is now used in flight critical avionics, flight control, weapons, electrical power control, and propulsion control. 1553 was originally published in 1973 for use on the F-16 military aircraft program. The current version of 1553 is MIL-STD-1553B, Notice 2, implemented in 1986.
A number of companies provide components which implement the communication interface functions of 1553. Among them is the Model UT1553B BCRTM device, provided by United Technologies Microelectronics Center, Inc. ("UTMC") Colorado Springs, Colo. The BCRTM is a single IC that implements the three functions of 1553: bus controller, remote terminal, and monitor terminal. For more information on the UT1553B BCRTM consult the 1553 Product Handbook provided by UTMC, and U.S. Pat. No. 4,805,137, both of which are incorporated herein by reference.
However, as 1553 popularity and usage increases and IC fabrication techniques improve, there is a desire for 1553 interface devices that provide for a greater number of 1553 functions implemented on a single IC, and for increased flexibility in meeting 1553 interface design requirements.